Space signaling system.



H. P'.-PERKINS. SPACE SIGNALING SYSTEM.

APPLICATION FILED JULY 29, 1909.

Patented Sept.30,1913.

2 SHEETS-SHEET l.

v ZZi-II Inventor. Harry F Perkms,

'JTtty.

H. F. PERKINS.

SPACE SIGNALING SYSTEM. APPLIGATION FILED JULY 29, 1909 Patented Sept. 30, 1913.

2 SHEETS-SHEET Z 1 7 \Nltnesses. J4 Inventor; 46M Harry F. Perkins,

considerable diiiiculty.

nann r. ruaxrus,

6F $GHENECTA1DY, NEW YORK, ASSIGNOZR, 'IO GENERAL ELECTRIC CQMPANY, 4h CORPORATIQN OF NEW -0?.K.

SPACE SIGNALING SYSTEM.

Specification of Letters Patent. Patented; Sept. 3%, 1913;

Application filed J u1y'29. 1909. Serial No. 510,196.

To all whom it may concern Be. it known that I, HARRY F. PERKINS,

a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Space Sig naling Systems, of which the following is a specification. I

My invention relates to sending instru ments for space signaling, or any other similar class of apparatus in which it is necessary to frequently interrupt heavy dynamic currents.

In high-powered wireless telegraph stations it J. S frequently customary to work with currents of forty to fifty kilowatts, or even greater amounts of energy. As is to be expected, the rapid interruption of heavy currents when sending messages introduces Heretofore oil switches have been used for this purpose,

but the continued and severe arcing rap dly destroys the metallic contacts.

Two kinds of currents are employed in space signaling, namely, "alternating currents, which, as is Well known, rise and fall between zero and maximum value and reverse in polarity; and pulsating currents, which rise and fall between minimum and maximum value without reversing in polarity. These two kinds of currents will hereinafter be referred to under the gene al term of periodic currents. v

According to my invention, a mercury vapor device is included in the main circuit, by which, as will be explained, the circuit is broken when sending messages.

The mercury-vapor device comprises essentially a mercury electrode and a cooperating electrode, both contained in an exhausted envelop, and through which. as is well known, a current will readily'fiow when an arc has once been started. The are breaks when the impressed volt-age falls below a certain minimum value, thus opening the circuit. This nlercury-vapor device is provided with an auxiliary starting device for rvuclcling the space between the mercury .=il-0 and the coiiperatiug electrode conductive. in the present instance the start 511;; device consists of a supplemental electrode, which draws an are maintained by direct current. As its operating current is small the circuit containing the auxiliary arc can be interrupted at will by the operator with use of a suitable switch,suchv as an ordinary telegraphers key. As long as the auxiliary arc 1s maintained the main arc is kept alive; but when the auxiliary arc is interrupted by opening its circuit the main arc breaks when the voltage of the periodic current falls below the minimum value necessary to maintain it.

Preferably current'passing through the vapor device and interrupted thereby is of.

low voltage and high amperage, and is-- transformed to any desired higher voltage before being sent out as electromagnetic waves.

My invention will be mor'e'geadily understood by reference to the following drawing,

in which Figure 1 1s a simple diagram of circu ts, showmg the arrangement 1n which a half wave of an alternating current is utilized. 'Thls arrangement, therefore, furnishes a pulsating current. According to the arrangement shown in Fig. 2, both half waves of an alternating current are utilized by the use of two mercury vapor devices. Fig. 3 is a somewhat modified arrangement, simi larly utilizing both half waves of an alternating current using but one mercury-vapor device. Fig. 4 is a cross-sectional view, showing details of the mercury-vapor de vice;- and Fig. '5 is a sectional detail view of the auxiliary starting electrode.

Referring to Fig. 1, it will be seen that the mercury-vapor device 1 is in series'with the secondary of a. step-down transformer 2 and the primary of a step-up transformer as shown diagrammatically in this figby a storage battery 8 or other suitable source of direct current; The circuit, including the solenoid 7 and storage battery 8, is opened and closed by a switch, such as the key 9. To the secondary of the transformer 3 is connected any suitable sending apparatus used in space telegraphy, such as stead of one are employe' utilizing both half waves of the alternating current. The circuit through device 15 is completed by conductors 16 and 17. The clrcu t through the device 18 is completed throng conductors 19 and 20. Each devic eis provided with its own starting circuit, "both of which are closed and opened simulfneously by a double contact switch 21. 'I, e circuitfor converting the ener y into electromagnetic waves, as illustrate is the same as that shown in Fig. 1.

As shown in Fig. 3, a single envelop 22, containing a common. mercury electrode 23 and two positive electrodes .24, 25, 1s employed. The electrodes 24 and 25 are connected to a source of energy, such as a compensator 26, the central point of which is connected to the mercury electrode 23 by conductor 27. In'circuit with each of the electrodes 24, 25 is included the primary of transformers 28, 29. The secondaries of these transformers are reverse-connected to a common circuit, which is in turn c0nnected to the primary of a step-up transformer 30. The secondary of transformer 30 is connected to a resonant circuit, as described in connection with Fig. 1, for converting the energy into electromagnetic waves. The device 22 is provided with a single starting electrode 31, which similarly to the starting electrodes shown in Figs. 1 and 2, is operated by a storage battery 8, the circuit being interrupted by a key 9.

As shown in detail in Fig. 4, the mercuryvapor device consists of a container 32, which has a cover 33 bolted thereon in such a manner as to make an air-tight joint. The cover is separated from the walls of the container by aluminum or copper washers 34, and the two surfaces are firmly drawn together b tightening the nuts 35. Passing througi the cover and making an air-tight joint therewith is the positive electrode 5. It is separated from the cover by an insulating fiber bushing 36. The flange 37, consisting of copper or other metal, is welded to the stem 38 of electrode 5. Above the flange 37 is situated a fiber block 39. Above we block I seal is maintained a't'this point.

39 is a spring 40, upon which pressure is exerted by the yoke 41, which is attached to the cover 33 by the bolts 42, 43. By the tightening of bolts 42, 43, pressure is. transmitted by the spring 40 to the fiber block 39 and flange 37, and in this manner a perfect The stem 38 does not come in contact with the spring 40 pr the yoke 41,. and, therefore, the stem 38 is entirely insulated from the metal container. It is surrounded by a sleeve 44 of insulating material, such as porcelain. The insulating washer 36 is rotected from the heat of the are by a lava ushing 45.

The joint of the auxiliary electrode and of 0 Ver is somewhat similar to that already desc ibed in connection with the main electrode 5. As shown in detail in Fig. 5, the metal parts are insulated from the cover 33 by insulating sleeve 46. Pressure is trans-- terial, as nickelsteel, slides a core 53 of magnetic iron, to which is tapped a stem 54 with a flange sliding through non-magnetic metal bushing 55. Surrounding this joint is an insulating sleeve 56, wh ch by the aid of the fiber bushing 46 serves to support and hold in place the refractory insulating sleeve 57 surrounding the stem 54 of the plun 1. To the top of the plunger core 53 is attac .ed a guide washer 58 of graphite or other suitable material, to which is attached in turna spring 59 serving to force down the plunger core when the magnet coil 52 is definergized, and to assume electrical contact between the plunger and the frame. The upward motion of the plunger is arrested by the flange on the stem 54, and its downward" motion by the.core 53. I

The casing 32 is evacuated thro'ugh tube 60 welded into the wall. The refractory ring 61, consisting of silica or similar re-.

electrodes 6 and 4 renders the space between electrodes 4 and 5 conductive and starts an are between the same for the successive half waves of the alternatin -current impressed upon transformer 2. urrent flows only when its polarity is such as to make the mercury electrode a a cathode. Therefore, a pulsating current is supplied to transformer 3, where it is stepped up to a higher. potential and is utilized for the production of electronic" ietic waves in the well'dm'own manner. en the switch 9 is open the auxiliary arc is broken, and the are between electrodes 4 and 5 goes out when the impressed voltage falls below the value necessary to maintain the arc. Therefore, by opening and closing the key the operator can make the dot and dash signals of the Morse code, or any other code, the heavy dynamic current being in each case broken by the inherent action of the mercury vapor device without damaging any contacts.

The operation of the system according to Fig. 2 is very much similar; but in this case when the key 21 is closed an auxiliary arc in both the mercury-vapor devices. 15 and 18 is started by the lifting of the auxiliary electrodes; Therefore, when the polarity of the current is such asto make the mercury electrode in device 15 cathode, a current will flow through circuits 17 and 16 to the device 15, and when the polarity reverses current will flow through circuits 20 and 19 through the device 18. An alternating current, therefore, is supplied to the transformer 3, where it is stepped up to higher potential and utilized for the production of electromagnetic waves.

- Fig. 3 shows the mercury electrode with two cooperating electrodes; When the key 9 is closed an auxiliary arc is started between the e'lectrcde 31 and the mercury electrode 23, which renders the space within the container conductive, so that the current flows alternately between electrode 23 and electrode 94 during one-half'wave of the alternating current, and between electrcde 23 and electrode during the other half wave of the altern current. When a can rent iiows through the primary of transformer 29 during one-half wave of the alternating current, current is impressed from its secondary upon the primary of transformer 30. During the other half wave, current is flowing through the primary of transformer 28, and is likewise supplied to the primary of transformer 30. It will, therefore, be seen thalt an alternating current flows during the time the key 9 is depressed through the primary of transformer 30. It is delivered at the desired voltage from the secondary of transformer 30 to the resonant sending circuit, which is identical to that shown in Fig. 1. As soon as the auxiliary arc is broken a and, therefore,

'ent of said source for rendering at will thereby striking an arc ,sou cc or direct current, a v

the main arc goes out when the voltage falls below the minimum Voltage necessary to maintain the same.

The action of the spring 59,- assisted by gravity, returns the auxiliary starting electrode quickly to the mercury surface, Where it remains in readiness to be again lifted, makes the operation of the device quick and positive.

-What I claim as new and desire to secure by Letters Patent of the United States, is

1. The combination of a source of current of consul able energy periodically passing through zero, a vapor electric device included in circuit therewith, means independconductive at will continuously during desired intervals in accordance with signals to be transmitted, and means current impulses transmitted by said device for the production of signals.

2. In a systemof signaling, the combination of a source of current of considerable energy periodically falling tozero, a inercury arc with, and means independent of said source for starting an arc and maintaining the arcing space conductive during desired intervals in accordancewith signals to be conveyed.

3. In a system of signaling, the combina' tionv of a source of alternating current of moderate potential and large current value, a mercury vapor device in circuit therewith, a source of direct current of moderate energy, means operative thereby to render said mercury vapor device conductive at will and an oscillation circuit for utilizing the energy transmitted through said device for the production of electromagnetic waves.

4. In a system of signaling, the combination of a source of periodic current, a vapor for utilizing the device included in circuit there said device electric device included in circuit therewith,

electrodes in said device for maintaining an auxiliary arc, a local circuit carrying on. rent cf small energy to sustain said iliary arc and means in said lt al for controlling the supply of at cordance with signals to be trans-m 5. In a signaling system, the cc-rnfoi. of a source of alternating current, a. electric device having a vaporizahle c2 and a main anode, a supplemental elect; ode urged intocontact with the cathrtle, a source of current connects mental electrode and oaths for withdrawing the'euppler ca, t.

fr m the cat ode, during in render device conductive the space in the vapor during said intervals.

6. system of signaling, ti tio l'il a source of peric dev ace having n electrod es for periods varying in duration in accord ance with the signals to be conveyed. 10

In witness whereof, I have hereunto set my hand this 27th day of Jul 1909.

HARRY E. ERKINS. itnegses B JAMIN B- HULL, LULU A.I-IA1\ILTON, 

